A bone scan uses small amounts of radioactive materials (radiotracers) and a computer to create an image of the skeleton. The image shows changes or abnormalities in bones. A bone scan is also called bone scintigraphy.
Why a bone scan is done
A bone scan helps doctors diagnose and evaluate different bone diseases and conditions. It may be done to:
- find bone cancer or determine if cancer from another area has spread to the bone
- help diagnose the cause or site of unexplained bone pain
- help diagnose broken bones that are not clear on an x-ray
- see how far the cancer has spread
- find damage to the bones caused by infection or other bone conditions
- find out if cancer treatment is working or as part of follow-up
How a bone scan is done
A bone scan is usually done as an outpatient procedure in the nuclear medicine department of a hospital. Special preparation is not usually needed. If you are breastfeeding, are pregnant or think you might be pregnant, tell the doctor or staff in the nuclear medicine department before the scan.
You will be asked to wear clothing that has no metal zippers, belts or buttons. You will be asked to remove your glasses, jewellery and most or all of your clothes. You will be given a cloth or paper gown to wear for the test.
Your arm will be cleaned and a small amount of a radiotracer will be injected. The radiotracer travels through your blood to the bones and organs. It takes about 3 to 4 hours for it to collect in your bones. During this time, you may be asked to drink 4 to 6 glasses of water to wash the tracer that does not collect in your bones out of your body. You will be asked to empty your bladder before the scan.
As the tracer wears off, it gives off some radiation that is detected by a camera that slowly scans your body. The scanning part of the test takes about 1 hour. The scanning camera may move above and around you while you lie very still. You may be asked to change positions. You may be scanned right after the injection and again after 3 to 4 hours.
After the scan, the radiotracer quickly loses its radioactivity. It passes out of the body through urine (pee) or stool (poop) within the first few hours or days after the test. The amount of radiation is small (similar to an x-ray). It’s OK for people to come in contact with you after the test.
You will be given instructions for special precautions after the test. Drinking fluids helps flush the radiotracer from your body. It is important to wash your hands thoroughly with soap and water after using the toilet. You may be instructed to flush the toilet twice immediately after using it.
You may have soreness or swelling at the injection site. In very rare cases, allergic reactions to the radiotracer can happen.
What the results mean
A normal bone scan shows the radiotracer spread evenly among the bones, and no areas have too little or too much tracer.
An abnormal bone scan shows hot spots or cold spots.
- Hot spots are areas of bone where the tracer has collected. Hot spots can be caused by bone cancer, arthritis, a bone infection or disease.
- Cold spots are areas of bone where there is no tracer. Cold spots can be caused by a certain type of cancer, such as multiple myeloma, or a lack of blood supply to the bone.
What happens if the results are abnormal
Your doctor may recommend more tests, procedures, follow-up care or treatment.
Special considerations for children
Preparing children before a test or procedure can help lower their anxiety, increase their cooperation and develop their coping skills. This includes explaining to children what will happen during the test, such as what they will see, feel and hear.
Preparing a child for a bone scan depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.